The diversity of research in cell biology and biochemistry disciplines share a common denominator in the quantitation of cellular components, in particular of nucleic acids and proteins. Breakthroughs in molecular biology and recombinant DNA technology have provided a wide array of experimental techniques for such quantitation that include a variety of macromolecular separation and blotting procedures using both radioactive and non-radioactive reagents. A serious limitation of these techniques is signal quantitation, because the detection methods invariable have a narrow dynamic range. PhosphorImager-FluorImager represents a major breakthrough in increasing the dynamic range for signal quantitation by an order of magnitude or more over that of conventional densitometry of autoradiograms or stained gels. The PhosphorImager is already being extensively used to quantitate radioactivity via storage phosphorescence without film exposure. Recent innovations in the FluorImager "STORM" System provide a unique addition to this quantitation using fluorescent probes. Apart from the advantage of avoiding the use of radioactivity, fluorophores providing exciting opportunities for quantitating nucleic acids and proteins present in various forms. Use of the multi-user FluorImager will result in a significant saving in money and time for the investigators. The Storm System from Molecular Dynamics is extremely versatile in having three detection capabilities. As a gel/blot imaging system, it can utilize storage phosphor autoradiography, direct fluorescence for nucleic acid and protein gel analysis, along with chemifluorescence, which is a major breakthrough development for fast and sensitive quantitation of DNA and proteins. This FluorImager, the first such equipment at UTMP, Galveston, will be extensively used as shared equipment mostly for fluorescence measurement methods, not only by the NIH-funded principal and co-investigators listed in the application, but also by other investigators as time permits.